Born in Bridgend in 1920, Matthews attended Bridgend County School before going on to study medicine at the University College Cardiff. As a youth he was a keen sportsman and won the Welsh AAA junior 220 yards title in 1937.
With the outbreak of the Second World War, Matthews applied to join the Royal Air Force, but was required to train as a doctor at the Welsh School of Medicine.
Matthews was later commissioned into the Royal Army Medical Corps. Bleddyn Williams, an RAF trainee and later Matthew's centre partner for Wales, played with Matthews for the first time whilst stationed in South Wales.
During his time at RAF St Athan air base in the Vale of Glamorgan in 1943, Matthews fought future world champion Rocky Marciano in an amateur boxing match. Marciano famously ended his career having won every professional match he had fought, but Matthews held him to a draw.
Matthews played centre for Wales and Cardiff, forming one of the greatest midfield pairings Wales has ever had with Bleddyn Williams. He went on to play 17 Tests for Wales and six for the British and Irish Lions on their 1950 tour of New Zealand and Australia, and was the team doctor for the 1980 British Lions tour to South Africa.
Speaking of the sad news, Cardiff Blues Chairman Peter Thomas said,
"Jack Matthews was undoubtedly one of the greatest centres Wales has ever produced and formed a formidable centre partnership with his great friend Bleddyn Williams.
"He was a strong runner, a devastating tackler and showed his class not only for Cardiff but also for Wales and the Lions.
"He was an outstanding player in the '40s and '50s for Cardiff before being appointed Chairman of the club.
"Our thoughts and prayers are with his family at this sad time."
Cardiff Blues will be holding a minute's silence in memory of Dr Jack Mathews OBE ahead of their first home league match against Edinburgh in September.